Method of making turnbuckles.



UN ITED ST'A'IES PATENT OFFICE.

IDWLID I. JOHNSON, 0! 8'1. PAUL, IINNESOTA.

II'I'HOD OI ILKING TUBNIUCXLB.

"collection 0! letters Pete. I-

lutented Oct. 5, 1909.

Application fled larch 85, I900. lertat Io. 488,840.

To all whom it may concern:

Be it known that I, Enwaun I'I. Jonxsox, a citizen of the United Statesof America, and a resident of St. Paul, county of Rammy, State ofMinnesota, have invented certain new aml useful Improvcna-nts in Methmlsof Making 'Iurnbuckles, of which the following is a full and clearspecification. lllft'ltillfl. being bad to the accompanying drawings, inwhich- Figures 1 and 2, respectively, a plan aml a transverse section ofthe blank from which the buckle is constructed; Figs. 3 and 4,respectively, a plan and a cross-section showing the appearance of theblank after the first operation; Figs. 5 and 6 similar views of thedevice after the second operation: Figs. 7 and 8 similar views of theproduct after the next operation: Figs. 9 and ltl similur views of thearticle after the next operation; Figs. ll and 12 similar views of thecoin ileted article.

'1 e object of this invention is to )rovide a simple and inex nsivemethod 0 maimfacturmg li ht an strong rod-con lings of the turn-bu tletype, that is a tubulitr cou ling such as shown in Fig. 1'2, consistingo a central enlarged portion, polygonal in cross section to adapt it toreceive a tool, and reduced end portions internally threaded forconnection to the externally threaded adjacent ends of the rod sections.In carry- 1 out this method I take a circular flat di of sheet metal anddraw or stamp it to a cup form such as shown in Fi '3 and 4; and then Idraw this cup still eeper to the form shown in Figs. 5 and ti. 1 then,by suitable dies draw this cup down to the )eculiar shape shown in Figs.7 and 8, that is with its main or upper part polygonal in cross sectionand its lower portion narrowed down to form one of the necks at the endsof the coupling. I then, by a still further draw operation, elongatethis ferrule-like cup ai i g then open the lower end of the cup bycutting it oil or otherwise, as shown in Fig. 10. I then place thecoupling in a suitable die and neck or narrow down by com- I pressionthe upper end of the tube, any suitable die arran'ement being used forthis pur mse, such, or instance, as the die shown [It big. 4 of myco-pendii application 5cria No. 4:33.239. '1 he nedli portions of thecoupling are then threaded internally to complete the coupling. In thismanner a strong light coupling can be made at a minimum expense forlarge quantities. lly drawin the couplin in the manner set forth t nocoupling wi I be made of a single homogeneous eompactedpiece of steel.

It will be observed that by my method I avoid weakening the tubularblank by radial expansion or stretching but on the contrary reatlystrengthen the reduced end-portions by bodily compressing the metalinwardly and thus puttin" it under radial com ression. There wilfnoteven be any stretc ling or bulgin of the blank at the vertical cornersof t to mandrel c as the distance between these corners and the internalwall of the die is equal to the thickness of the wall of the blank.

Havin thus fully described my invention, what I c aim as new, and desireto secure by Letters Patent, is

The method herein described of making turn-buckle rod-couplings from asheet meta cup having a closed bottom, consisting in drawing down thecup to the desired depth and simultaneously compressing and narrowingthe lower end of the cup to a cylindrical form and the upper portioninto a hexagonal shape in cross-section throughout its length, thenopening the lower closed end of the cup, and then reducing the upper endby com nession to a narrow cylindrical shape, for t no purpose setforth.

In testimony whereof I hereunto allix my signature in the resence of twowitnesses this 6th day of It arch, 1908.

EDWARD E. JOHNSON.

.Witnesses:

G. M. Aur za, E. C. (ioommu.

